Glass polishing head having a detachable felt pad



ct. 17, 3967 W. F. ARMSTRONG GLASS POLISHING HEAD HAVING A DETACHABLEFELT PAD Filed Feb. 17, 1964 INVENTOR. JM L/ JM F fifFMSTWM/G,

United States Patent 3,346,904 GLASS POLISHING HEAD HAVING A DETACHABLEFELT PAD William F. Armstrong, Newburgh, N.Y., assignor to American FeltCompany, Glenville, Conm, a corporation of Massachusetts Filed Feb. 17,1964, Ser. No. 345,216 2 Claims. (Cl. 15-23012) The present inventionrelates to the art of polishing glass and particularly to a new andimproved combined felt pad and attaching means for use with polishingheads of glass polishing machines.

It is presently customary to employ square shaped felt pads having asize such that an inscribed circle of the square equals the diameter ofthe round polishing head of a glass polishing machine. The exposedcorners of the square felt pad are bent upwardly about the peripheraledge of the head, and a metal band is clamped about these bent-up edges,thereby securely holding the felt pad to the polishing head. Such feltpads also have been secured to the polishing head by a cementing processemploying hot pitch or other adhesives.

The bent-up corners of prior known polishing pads provide a point ofweakness, and the pads often tear at such corners, rendering themuseless long before the normal life of the felt has been consumed.Furthermore, such square pads require a high percentage of unusable feltin the bent-up corner portions.

Cementing felt pads directly to the iron polishing head isunsatisfactory because the down time of a polishing machine to effectreplacement of such a pad is excessive. It involves the removal of anadhering pad from a polishing head, the cleaning of the head, theapplying of fresh adhesive to the head, and the application of new feltwhich requires a predetermined curing time before the polishing machinecan be restarted. When it is considered that there are many polishingheads in one machine and that felt replacement usually is necessary, itbecomes apparent that rapid replacement of felts is an essentialrequirement.

An important object of this invention is to provide a combined felt padand attaching means for the heads of glass polishing machines which canbe replaced with a minimum of down time of the polishing machine.

Another object of this invention is to provide such a felt and attachingmeans which will substantially reduce labor costs in replacing the same.

Still another object of this invention is to provide such a felt andattaching means in which a minimum of felt is required for maximumpolishing action. a

Another object of the invention is to provide such a felt and attachingmeans which may be disposable.

In one aspect of the invention, a glass polishing head may comprise adisk of metal having a centrally disposed stem or spindle extending fromthe disk at right angles thereto. The stem is adapteclto'be connectedto'rotating means Within a glass polishing machine, which rotating meansmay be reciprocable axially of the stem to raise and lower the polishinghead from contact with the glass being polished.

In another aspect of the invention, a flexible sheet having a largenumber of closely spaced hooking elements made from flexible resilientfibers may be attached to the face of the glass polishing head oppositethat from which the stem or spindle extends. The hooking elements may bemade from any flexible resilient fiber that will stand erect. One formof sheeting is a woven nylon textile having upstanding loops that havebeen cut to form hooks. One such material is shown, described andclaimed in US. Patents 2,717,437 and 3,009,235.

The hooked material may be permanently attached to means for attachingthe Patented Oct. 17, 1967 the face of the polishing head by anadhesive. For example, the textile backing containing the hooks may beprecoated with a solvent activated precoat which, prior to being appliedto the metal surface, is treated with a solvent such as methyl ethylketone. Applying the hooked textile to the face of the polishing headsecurely and tenaciously unites the two.

In another aspect of the invention, a felt polishing pad of the exactdiameter of the metal polishing head may have attached to its back facea woven textile sheet having a great number of upstanding loops thereonsuch as disclosed in the above-referred-to patents. This looped textilesheet may be attached to the felt pad by stitching, stapling oremploying an adhesive such as by having a solvent or heat activatedprecoat on the back face of the looped textile sheet. Methyl ethylketone can be employed as an activating solvent or heat can be used asan activating means.

It has been found that firmly pressing the face of the felt pad havingthe looped textile sheet against the hooked surface of the textile sheeton the polishing head causes the felt pad to be securely held to thehead by the mechanical interlocking of the hundreds of hooks and loops.It has also been found that such a connection provides exceptionallyhigh torsional holding power, which is particularly desirable in thepolishing of glass.

In still another aspect of the invention, the hooked and looped textilesheeting may be applied to either the polishing head or the felt pad,but preferably the hooked textile is applied to the polishing head.

In still another aspect of the invention, the hooked or looped textilemay completely cover the polishing head and various tabs of less areamay be applied in desired arrangements to the felt disk, and annularforms may be used which latter provides an arrangement facilitating apumping action of the center, unconnected portion of the felt pad.

The above, other objects and novel features of the invention will becomeapparent from the following specification and accompanying drawing whichare merely exemplary.

, In the drawings:

FIG. 1 is a perspective view of a glass polishing head and pad to whichthe principles of the invention have been applied;

FIG. 2 is a perspective view of a glass polishing head and pad to whichthe attaching means of the present invention has been applied but of aform different from that shown in FIG. 1;

FIG. 3 shows another modified arrangement of the pad to the glasspolishing head;

and

FIG. 4 is an enlarged sectional view means of the present invention.

Referring to the drawings, and particularly to FIG. 1, the principles ofthe invention are shown as applied to a glass polishing head including ametal disk 10 having a centrally disposed spindle or stem 11 extendingtherefrom. The stem 11 is adapted to be connected to a rotatable drivingmember of the glass polishing machine that is reciprocated in adirection axially of the stem 11 to raise and lower the polishing headwith a felt attached thereto off and onto a glass plate being polished.

A sheet of woven textile 12 may be attached to the face of the polishinghead 10 by any suitable means. Preferably, the woven textile sheet 12 isprovided with a precoat on its back face which is adapted to beactivated by a solvent such as methyl ethyl ketone.

Referring to FIG. 4, the sheet 12 may include hooked elements 13extending at substantially right angles to sheet 12. The elements 13 maybe of flexible resilient material of any sort capable of accomplishingthe desired results.

of the attaching The only critical characteristic is that the hookshould be sufficiently flexible to permit its flexure for a purpose tobe described later. Although the hooked elements 13 may be of anysuitable material, a sheet material known by the trade name Velcro hasbeen found to be satisfactory. This material is shown, described andclaimed ,in US. Patent 3,009,235. It utilizes plastic suchas nylon asthe thread that forms the hooked elements 13, or any other threadmaterial that can be heat set. However, the hooked elements 13 may evenbe made from a flexible wire suitably penetrating a backing sheet andfirmly secured therein. There area great number of the hooked elements13 per square inch of the sheet material. The back of the sheet 12 maybe provided with a solvent activated precoat for purposes of forming anadhesive for securing the sheet 12 to the front face of the polishinghead 10. A precoat that is activated by methyl ethyl ketone has beenfound to securely hold the sheet 12 to the metal face of the polishinghead 10.

A felt polishing pad 14 of usual construction may have a textile sheet15 applied to its one face. The textile sheet 15 may include a profusionof loops 16 extending upwardly from the sheet. There may be hundreds ofsuch loops per square inch and they are usually substantially softer orless rigid than the hooked elements 13.

The sheet 15 may be attached to the pad 14 by stitching, stapling or byan adhesive such as the solvent activated precoat employed with thesheet 12.

The construction is such that aligning the pad 14 with the head andfirmly pressing them together causes the hundreds of hook elements 13per square inch to engage hundreds of loops 16 per square inch, so thata firm, mechanically interlocked bond is formed between the sheets 12and and consequently the pad 14 is firmly attached to the head 10'.Since the mechanically interlocked connecting means is particularlystrong in torque resistance, it is especially suited for use inattaching felts to a polishing head.

When the felt pad 14 becomes worn, it is only necessary to pry it offthe head 10 by a peeling action, the connecting means having its minimumresistance to separation by peeling.

In the embodiment shown in FIG. 2, the sheets 12 and 15 are annular inform, providing a central unattached portion of the felt pad 14. Thisarrangement acts to provide a pumping action of the felt pad 14 as thehead 10 is raised otf and lowered onto the glass being polished.

Such action permits the slurry employed in polishing to feed into andout of the porous felt pad 14.

In the embodiment shown in FIG. 3, the connector sheet 12 issubstantially the same as that of FIG. 1, whereas inwardly extendingstrips 17 are applied to the one face of the pad 14, and patches 18 areapplied between the segments of the pad 14 formed between the strips 17.This arrangement reduces the area of felt pad requiring connectingmeans.

If desired, a layer of canvas could 'be put on the felt pad by adhesiveand one of the base material or sheet means fastened thereto by anadhesive, such then being joinable to the head base material.

Still further, one of the base sheets could be fastened to a sheet ofcanvas and the canvas fastened to the material polishing head by acircular band (not shown), the other base sheet means on the felt padthen being joinable to the head base sheet as described previously.

Although the variousfeatures of the improved polishing head and pad havebeen shown and described in detail to disclose several embodiments ofthe invention, it will be evident that changes may be made in suchdetails and certain features may be used without others without departing from the principles of the invention.

What is claimed is:

1. A polishing head for glass polishing machines comprising incombination, a flat disk having a spindle at- ,tached to one facethereof, a felt polishing pad having substantially the same area as thatof said disk, circular ring shapedsheet means conforming to andvadhesively secured to each of said disk and pad, said sheet means havinga multiplicity of closely spaced interengageable hooking elementsthereon, the hooking elements on one of said sheet means being offlexible resilient material having hooks at the ends thereof and thehooking elements on the other sheet means being in the form of loops,each of said sheet means being open and unattached in the center thereofwhereby when said opposing surfaces of said sheet means are pressedtogether the hooking elements and loops are interengaged and theunattached center portion of said pad may move relative to said sheetmeans and disk to provide a pumping action of the felt when the head israised and lowered on the glass being polished.

2. A polishing head for glass polishing machines com prising incombination, a flat disk having a spindle attached to one face thereof,a feltpolishing pad having substantially the same area as that of saiddisk, disk sheet means conforming to and adhesively secured to saiddisk, and a series of radially extending opposed strips and patchesangularly arranged thereinbetween and also in opposed relation, saidstrips and patches being adhesively secured to said felt pad, said disksheet means and said strips and patches having a multiplicity of closelyspaced interengageable hooking elements thereon, said hooking elementshaving hooks and loops on the ends thereof whereby when said disk andpad are pressed together the hooking elements and loops therebetween areinterengaged.

References Cited UNITED STATES PATENTS 2,286,208 6/ 1942 Kirchner51-4-06 2,544,940 3/1951 Ritterbusch et al. 15-230.19 2,717,437 9/1955Mestral 24-205.l35 2,976,914 3/1961 Miller .l6-1-48 3,127,259 3/ 1964Boylan 24204 X 3,143,895 8/1964 Robie.

FOREIGN PATENTS 80,153 2/1963 France.

CHARLES A. WILLMUTH, Primary Examiner.

DANIEL BLUM, Examiner.

1. A POLISHING HEAD FOR GLASS POLISHING MACHINES COMPRISING INCOMBINATION, A FLAT DISK HAVING A SPINDLE ATTACHED TO ONE FACE THEREOF,A FELT POLISHING PAD HAVING SUBSTANTIALLY THE SAME AREA AS THAT OF SAIDDISK, CIRCULAR RING SHAPED SHEET MEANS CONFORMING TO AND ADHESIVELYSECURD TO EACH OF SAID DISK AND PAD, SAID SHEET MEANS HAVING AMULTIPLICITY OF CLOSELY SPACED INTERENGAGEABLE HOOKING ELEMENTS THEREON,THE HOOKING ELEMENTS ON ONE OF SAID SHEET MEANS BEING OF FLEXIBLERESILIENT MATERIAL HAVING HOOKS AT THE ENDS THEREOF AND THE HOOKINGELEMENTS ON THE OTHER SHEET MEANS BEING IN THE FORM OF LOOPS, EACH OFSAID SHEET MEANS BEING OPEN AND UNATTACHED IN THE